päikesetegevus

Päikesetegevus refers to the dynamic and ever-changing phenomena occurring on and within the Sun. It is driven by the Sun's internal magnetic field and manifests in various observable features. The most prominent aspects of solar activity include sunspots, solar flares, and coronal mass ejections.

Sunspots are temporary phenomena on the Sun's photosphere that appear as darker spots compared to surrounding areas. They are regions of reduced surface temperature caused by concentrations of magnetic field flux that inhibit convection. Sunspots often appear in pairs and can grow and shrink over time.

Solar flares are sudden, intense bursts of radiation and energy from the Sun's surface. They occur when magnetic energy that has built up in the solar atmosphere is suddenly released. Flares can emit a broad range of electromagnetic radiation, from radio waves to X-rays and gamma rays, and can also accelerate charged particles.

Coronal mass ejections (CMEs) are large expulsions of plasma and magnetic field from the Sun's corona. They are often associated with solar flares and sunspots, but can also occur independently. CMEs can travel outwards into space at high speeds, carrying with them billions of tons of solar material.

The level of solar activity follows an approximately 11-year cycle, known as the solar cycle. During solar maximum, sunspots, flares, and CMEs are more frequent and intense. During solar minimum, these phenomena are less common. Solar activity has a significant impact on Earth, affecting satellite operations, power grids, and radio communications through space weather.